Toshiba RAS-M07G3DV-E Service Manual page 23

1. Be sure to make setting so that liquid can be charged.
2. When using a cylinder equipped with a siphon, liquid can be charged without turning it upside down.
R410A Model
It is necessary for charging refrigerant under condition of liquid because R410A is mixed type of refrigerant.
Accordingly, when charging refrigerant from the refrigerant cylinder to the equipment, charge it turning the
cylinder upside down if cylinder is not equipped with siphon.
R32 Model
R32 refrigerant is a Single-component refrigerant that does not change its composition.
Although it is possible to charge the refrigerant with either liquid or gas, charge it with liquid.
(If using gas for charging, composition of the refrigerant changes and then characteristics of the air conditioner
change.)
[ Cylinder with siphon ]
Gauge manifold
Refrigerant
cylinder
Electronic
balance
3-4. Brazing of Pipes
3-4-1. Materials for Brazing
1. Silver brazing filler
Silver brazing filler is an alloy mainly composed of
silver and copper. It is used to join iron, copper or
copper alloy, and is relatively expensive though it
excels in solderability.
2. Phosphor bronze brazing filler
Phosphor bronze brazing filler is generally used to
join copper or copper alloy.
3. Low temperature brazing filler
Low temperature brazing filler is generally called
solder, and is an alloy of tin and lead. Since it is
weak in adhesive strength, do not use it for
refrigerant pipes.
OUTDOOR unit
Electronic
balance
Fig. 3-3-2
1. Phosphor bronze brazing filler tends to react with
sulfur and produce a fragile compound water
solution, which may cause a gas leakage.
Therefore, use any other type of brazing filler at a
hot spring resort, etc., and coat the surface with a
paint.
2. When performing brazing again at time of
servicing, use the same type of brazing filler.
3-4-2. Flux
1. Reason why flux is necessary
• By removing the oxide film and any foreign matter
on the metal surface, it assists the flow of brazing
filler.
• In the brazing process, it prevents the metal
surface from being oxidized.
– 22 –
[ Cylinder without siphon ]
Gauge manifold
Siphon
OUTDOOR unit